{
  "id": 73962,
  "title": "Some confused questions about positive and negative purchase amount",
  "url": "/competitions/elo-merchant-category-recommendation/discussion/73962",
  "author_name": "yang fang",
  "post_date": "2018-12-07T04:14:25.938000",
  "votes": 1,
  "comment_count": 6,
  "views": 0,
  "content": "<ul>\n<li>1.Why does purchase amount contain positive and negative numbers？What does positive amount  mean? And what does  negative amount  mean?  </li>\n<li>2.Why does installments contain zero and negative numbers? What zero and negative numbers mean？ <br>\nThanks</li>\n</ul>",
  "messages": [
    {
      "id": 435771,
      "postDate": "2018-12-08T18:33:32.397Z",
      "content": "<p>Hi! They described in the dictionary of the dataset that \"purchase_amount\" is normalized:\nMean normalization:\nx' = x - mean ( x )  / ( max(x) - min(x) )</p>\n\n<p>if any purchased item is below the mean of the all the purchased items for example:\nx - mean(x)  &lt; 0 the value will be negative in the normalized list.</p>",
      "rawMarkdown": "Hi! They described in the dictionary of the dataset that \"purchase_amount\" is normalized:\nMean normalization:\nx' = x - mean ( x )  / ( max(x) - min(x) )\n\nif any purchased item is below the mean of the all the purchased items for example:\nx - mean(x)  &lt; 0 the value will be negative in the normalized list.",
      "votes": 1,
      "replies": [
        {
          "id": 435783,
          "postDate": "2018-12-08T18:57:09.210Z",
          "rawMarkdown": "",
          "isDeleted": true
        },
        {
          "id": 435795,
          "postDate": "2018-12-08T19:34:30.607Z",
          "content": "<p>Sometimes the word normalized is used in another context that is not the one that the theory explains, maybe they just subtracted the mean or did something else, hard to find to me the 6010603.97 is an outlier I'm only working with +/- 1.5 * IQR.</p>",
          "rawMarkdown": "Sometimes the word normalized is used in another context that is not the one that the theory explains, maybe they just subtracted the mean or did something else, hard to find to me the 6010603.97 is an outlier I'm only working with +/- 1.5 * IQR."
        }
      ]
    },
    {
      "id": 435607,
      "postDate": "2018-12-08T11:17:08.110Z",
      "content": "<p>RE: installments\nI think negative installments might be just missing values. It might also be \"cash\" transactions that did not create a debt on the part of customer, hence no installments were required. It is different from zero installments that might mean that the debt was carried for less than a month.  </p>",
      "rawMarkdown": "RE: installments\nI think negative installments might be just missing values. It might also be \"cash\" transactions that did not create a debt on the part of customer, hence no installments were required. It is different from zero installments that might mean that the debt was carried for less than a month.  ",
      "votes": 1
    },
    {
      "id": 434874,
      "postDate": "2018-12-07T04:54:01.697Z",
      "content": "<p>I think this value may be the result after post-processing(log, etc) of original values.</p>",
      "rawMarkdown": "I think this value may be the result after post-processing(log, etc) of original values.",
      "votes": 1,
      "replies": [
        {
          "id": 434877,
          "postDate": "2018-12-07T05:01:04.240Z",
          "content": "<p>This sounds reasonable. But what zero and negative  installments mean？</p>",
          "rawMarkdown": "This sounds reasonable. But what zero and negative  installments mean？",
          "votes": 1
        }
      ]
    },
    {
      "id": 434860,
      "postDate": "2018-12-07T04:14:25.940Z",
      "content": "<ul>\n<li>1.Why does purchase amount contain positive and negative numbers？What does positive amount  mean? And what does  negative amount  mean?  </li>\n<li>2.Why does installments contain zero and negative numbers? What zero and negative numbers mean？ <br>\nThanks</li>\n</ul>",
      "rawMarkdown": "* 1.Why does purchase amount contain positive and negative numbers？What does positive amount  mean? And what does  negative amount  mean?  \n*  2.Why does installments contain zero and negative numbers? What zero and negative numbers mean？  \nThanks\n",
      "votes": 1
    }
  ],
  "comments": [
    {
      "id": 435771,
      "author_name": "C4rl05/V",
      "author_url": "",
      "post_date": "2018-12-08T18:33:32.397000",
      "content": "<p>Hi! They described in the dictionary of the dataset that \"purchase_amount\" is normalized:\nMean normalization:\nx' = x - mean ( x )  / ( max(x) - min(x) )</p>\n\n<p>if any purchased item is below the mean of the all the purchased items for example:\nx - mean(x)  &lt; 0 the value will be negative in the normalized list.</p>",
      "votes": 1,
      "replies": [
        {
          "id": 435783,
          "author_name": "",
          "author_url": "",
          "post_date": "2018-12-08T18:57:09.210000",
          "content": "",
          "votes": 0,
          "replies": []
        },
        {
          "id": 435795,
          "author_name": "C4rl05/V",
          "author_url": "",
          "post_date": "2018-12-08T19:34:30.607000",
          "content": "<p>Sometimes the word normalized is used in another context that is not the one that the theory explains, maybe they just subtracted the mean or did something else, hard to find to me the 6010603.97 is an outlier I'm only working with +/- 1.5 * IQR.</p>",
          "votes": 0,
          "replies": []
        }
      ]
    },
    {
      "id": 435607,
      "author_name": "sergeman",
      "author_url": "",
      "post_date": "2018-12-08T11:17:08.110000",
      "content": "<p>RE: installments\nI think negative installments might be just missing values. It might also be \"cash\" transactions that did not create a debt on the part of customer, hence no installments were required. It is different from zero installments that might mean that the debt was carried for less than a month.  </p>",
      "votes": 1,
      "replies": []
    },
    {
      "id": 434874,
      "author_name": "Youhan Lee",
      "author_url": "",
      "post_date": "2018-12-07T04:54:01.697000",
      "content": "<p>I think this value may be the result after post-processing(log, etc) of original values.</p>",
      "votes": 1,
      "replies": [
        {
          "id": 434877,
          "author_name": "yang fang",
          "author_url": "",
          "post_date": "2018-12-07T05:01:04.240000",
          "content": "<p>This sounds reasonable. But what zero and negative  installments mean？</p>",
          "votes": 1,
          "replies": []
        }
      ]
    }
  ],
  "raw_markdown_by_id": {
    "435771": "Hi! They described in the dictionary of the dataset that \"purchase_amount\" is normalized:\nMean normalization:\nx' = x - mean ( x )  / ( max(x) - min(x) )\n\nif any purchased item is below the mean of the all the purchased items for example:\nx - mean(x)  &lt; 0 the value will be negative in the normalized list.",
    "435607": "RE: installments\nI think negative installments might be just missing values. It might also be \"cash\" transactions that did not create a debt on the part of customer, hence no installments were required. It is different from zero installments that might mean that the debt was carried for less than a month.  ",
    "434874": "I think this value may be the result after post-processing(log, etc) of original values.",
    "434860": "* 1.Why does purchase amount contain positive and negative numbers？What does positive amount  mean? And what does  negative amount  mean?  \n*  2.Why does installments contain zero and negative numbers? What zero and negative numbers mean？  \nThanks\n"
  }
}